When a fueling rate of fuel supplied to an internal combustion engine is rapidly reduced to a minimum engine fueling rate, the flow rate of intake air entering the engine may for some time period remain undesirably high. The resulting high air-to-fuel ratios cause the engine to produce exhaust gas having high oxygen concentration. In engines that include an exhaust gas recirculation (EGR) system, this then causes high oxygen content exhaust gas to circulate through the EGR system. When the fueling rate is thereafter increased above the minimum engine fueling rate, the NOx content of the exhaust gas produced by the engine may spike to a higher than desired level due to the high oxygen content of the exhaust gas being circulated through the EGR system. It is therefore desirable to control the EGR system in a manner that reduces the amplitude of NOx spikes resulting from engine transient events.